Shannow-
If you search for "interesting article" of some time back you will find a Toyota engineering paper dated 1997 that indicated testing showed a lower limit of 2.6 cp for proper wear protection. What a surprise that Motorcraft 5-20 has a HTHS value of 2.65
I suspect that the manufacturers have been testing 5-20 for at least a few years and found it OK as far as engine life is concerned.
I have switched from M1 0-40 to Motorcraft 5-20 in my Ford.
Stay tuned for my UOA in a few months. I expect that it will show as good a result as others who have begun using this new trend in -20 engine oil and posted excellant UOA results.
And keep in mind Terry's comments on what our -30 wt oils are really like under HTHS conditions!
...seems switching from -30 to -20 wt oils may not be such a big deal after all.
If you search for "interesting article" of some time back you will find a Toyota engineering paper dated 1997 that indicated testing showed a lower limit of 2.6 cp for proper wear protection. What a surprise that Motorcraft 5-20 has a HTHS value of 2.65
I suspect that the manufacturers have been testing 5-20 for at least a few years and found it OK as far as engine life is concerned.
I have switched from M1 0-40 to Motorcraft 5-20 in my Ford.
Stay tuned for my UOA in a few months. I expect that it will show as good a result as others who have begun using this new trend in -20 engine oil and posted excellant UOA results.
And keep in mind Terry's comments on what our -30 wt oils are really like under HTHS conditions!
...seems switching from -30 to -20 wt oils may not be such a big deal after all.